1. Field of the Invention
The present invention relates to bats for baseball and, more particularly, to a wood bat which is internally reinforced with a tubular core made of fiber reinforced plastic materials or metal and externally reinforced with an outer sleeve made of fiber reinforced plastic materials or metal.
2. Description of the Related Art
Wooden bats are most popularly used because they are the cheapest ones. However, wooden bats have numerous drawbacks, such as heavy weight and bad equilibrium. In other words, the center of gravity is biased to the side of the barrel end. The center of gravity of a wooden bat is at about 11 inches from the barrel end, however the ideal center of gravity should be at the area within 14˜14.5 inches from the barrel end. Due to the aforesaid drawbacks, it requires much effort to hit the ball with the bat, and the bat cannot drive the ball to a long distance. Further, a wooden bat is weak and easy to break, and produces severe shocks when hitting the ball.
In comparison to wooden bats, an aluminum bat is relatively lighter in weight, and has an ideal equilibrium. Therefore, the performance of an aluminum bat is superior to conventional wooden bats, and an aluminum bat is more durable than conventional wooden bats. Further, the price of aluminum bats is reasonable. However, an aluminum bat produces shocks, noises and dents at barrel when hitting the ball.
The recently developed bats made of fiber reinforced plastic (FRP) material have the ideal counterweight and equilibrium and high performance in hitting. Further, a FRP bat has a strong structural strength, and does not break easily. However, The problem is that the FRP bat is so expensive that it can not get a popular use.